Airflow-electric coupling for vacuum cleaner



AIRFLOW-ELECTRIC COUPLING FOR VACUUM CLEANER Filed Jan. 4, 1965 Aug. 29, 1967 M. E. BELICKA .ETAL

12 Sheets-Sheet l INVENTORS MICHAEL E. BELICKA ROBERT C. LAMPE BY JOHN J. MOUGHT-Y Aug. 29, 1967 v 3,339,168

I ELECTRIC COUPLING FOR VACUUM CLEANER Mv E. BELICKA- ETAL 12 sheets-sheet 2 AIRFLOW- Filed Jan. 4, 1965 INVENTORS E. BELICKA C. LAMPE MIC HA .ROBEE'? THEIR ATTORNEY 29, 1957 M. E. BELICKA ETAL 3,339,168

AIRFLOW-ELECTRIC COUPLING FOR VACUUM CLEANER Filed Jan. 4, 1965 12 Sheets-Sheet 15 INVENTORS MICHAEL E. BELICKA ROB RT C. LAMPE J'QH ;"I MOUGHTY THEIR ATTORNEY Aug. 29, 1967 M. E. BELICKA ETAL 3,339,168

AIRFLOWELECTRIC COUPLING FOR VACUUM CLEANER 12 Sheets-Sheet 4 Filed Jan THEIR ATTORNEY Aug. 29, 1967 M. E. BELICKA ETAL 3,339,168

AIRFLOW-ELECTRIC COUPLING FOR VACUUM CLEANER 12 Sheets-Sheet 2) Filed Jan. 1965 MOU GHTY m mm ma m am mac VL; NEW IA. F mQ M THEIR ATTOR N EY Aug. 29, 1967 M. E.BELICKA ETAL 3,339,153

AIRFLOW-ELEGTRIC COUPLING FOR VACUUM CLEANER Filed Jan. 4, 1965 I l2 Sheets-Sheet 6 lNVENTOhS MlCHAELfE, BELICKA ROBERT c. 'LAMPE JOHNF'4I MOUGHTY THEIR ATTORNEY Aug. 29, 1967 M; E. BELICKA ETAL AIRFLOW-ELEZCTRIC COUPLING FOR VACUUM CLEANER 12 Sheets-Sheet 7' Filed Jan.

INVENTORS MICHAEL E. BELICKA ROBERT C. LAMPE JOHN J. MOUGHTY BY THEIR ATTORNEY g 1967 M. E. BELICKA ETAL 3,339,163

AIRFLOW-ELECTRIC COUPLING FOR VACUUM CLEANER l2 Sheets-Sheet 1- Filed Jan 4, 1965 5 A 1 II INyENTORS MICHAEL uBELICKA ROBERT JOHN .'-J LAM P E MOUG HTY THEIR AT TOR N EY Aug. 29, 1967 M. E. BELICKA ETAL AIRFLOW-ELECTRIC COUPLING FOR VACUUM CLEANER 12 Sheets-Sheet I.

0 g 00 U) (D D O (D m REE 3 R Q t.

INVENTORS MICHAEL BELICKA ROBERT'OILAM PE J'OHN figQ/IOUGHTY THEIR ATTORNEY g- 29, 1957 M. E. BELICKA E'QI'AL 3,339,168

AIRFLOW-ELECTRIC COUPLING FOR VACUUM CLEANER Filed Jan. 4, 1965 12 Sheets-Sheet 10 INVENTORS MICHAEL E. BELICKA ROBERT C. LAMPE J'OHN I MOUGHTY THEIR ATTORNEY g- 1967 M. E. BELICKA ETAL 3,339,163

AIRFLOW-ELECTRIC COUPLING FOR VACUUM CLEANER 12 Shets-Sheet 11 Filed Jan. 4, 1965 INVENTORS MICHAEL E. BELICKA ROBERT C. LAM PE JOHN I MOUGHTY V%n/p THEIR ATTORN EY United States Patent 3,339,168 AIRFLOW-ELECTRIC COUPLING FOR VACUUM CLEANER Michael E. Belicka, Greenwich, Robert C. Lampe, Stamford, and John J. Moughty, Old Greenwich, Conn., asslgnors to Electrolux Corporation, Old Greenwich,

Conn., a corporation of Delaware Filed Jan. 4, 1965, Ser. No. 423,269 10 Claims. (Cl. 339-5) ABSTRACT OF THE DISCLOSURE A hollow plug member connected to one end of an electric conductor-carrying suction hose and a hollow rewith a pair of keys or tabs that include electric contactsv which are connected through slip rings with the conductor wire of the hose. When the plug member on the end of the hose is inserted into the receptacle, the keys on the outer plug enter the keyways of the insulating ring and a seal is effected between the end of the hose and the receptacle. If the outer plug member is now rotated the insulating ring of the receptacle is simultaneously turned, uncovering the stationary live contacts and making contact with the electric contacts included in the outer plug keys or tabs.

Our invention pertains, in general, to the cleaning of carpeted or rug covered surfaces by employing the effects of surface agitation and suction, simultaneously; and, in particular, to a coupling for effecting a sealed airflow connection between a conductor-carrying suction hose and the suction inlet opening of the tank unit of a vacuum cleaner while simultaneously effecting an electrical connection between energized electrical contacts located in the'region of the tank units suction inlet opening and the hoses conductors.

For convenience, the coupling provided by the invention is often referred to hereinafter as an airflow-electric coupling.

It has been found that there results a more thorough cleaning of carpets and rugs, especially those made from synthetic materials, when they are simultaneously brushed and vacuumed. In performing such a cleaning operation, a flexible suction hose which carries electrical conductors applies suction, created in the tank unit of a vacuum cleaner, to a carpet cleaning nozzle while, at the same time, the hose conductors conduct electricity from the tank unit to a motor which, together with a carpet-agitating brush rotated by the motor, is located in the cleaning nozzle. Much of the dust and dirt in the carpet is dislodged by brush rotation and conveyed by suction-induced airflow to a dust bag located in the tank unit. In addition, the rotating brush flulI's the carpet nap giving the carpet surface a neat appearance.

With the prior art cleaning equipment of the type hereinbefore described, a conventional air flow coupling at one end of the suction hose is used to connect the hose with the tank units suction inlet opening so that dirtladened air can flow through the hose and into the dust bag located in the tank unit. Also, in order to conduct electricity to the brush-rotating motor located in the cleaning nozzle, there is provided a separate electrical receptacle in the tank unit, at a relatively remote location from the suction inlet opening, and this receptacle is intended to receive a conventional male plug connected to one end of an electric cord which is carried lengthwise along the outer surface of the suction hose.

Although the prior .art cleaning equipment, hereinbefore briefly described, cleans rugs and carpets very well, it is not entirely satisfactory because of the separate airflow and electrical connections which are required to be made preparatory to the actual cleaning operation. Generally speaking, the prior art vacuum cleaner arrangement involving the aforesaid separate connections is somewhat unsafe, relatively unwieldy and it requires somewhat more than ordinary effort to set it up to prepare for the cleaning operation.

The aforementioned arrangement is-somewhat unsafe because the energized electrical contacts of the receptacle mounted in the tank unit are easily accessible, even though they are recessed. For example, a child, even a mildly curious one, can find ways to gain access to the receptacles contacts and sulfer an electric shock.

Also, the prior art arrangement is relatively unwieldly because although the conventional airflow coupling, which is rigidly connected to the end of the hose, is intended to permit rotative movement of the hose when the coupling is inserted in the suction inlet opening, such rotative movement is, nevertheless, very limited because of the somewhat restrained nature of the electrical connection between the cords male plug and the tank units receptacle. In order to provide an adequate degree of rotative movement a relatively large amount of slack must be provided in the electric cord. As a rule, this is undesirable. Sometimes, for example, a long slack loop portion of the cord will get fouled in the tank units wheels or runners.

Somewhat more effort is required to set up the prior art equipment for the cleaning operation. For example, after connecting the airflow coupling with the suction inlet opening, the cords male plug is inserted into the tank units receptacle, which because of its somewhat remote location on the tank unit may require additional handling of the tank unit (perhaps, to reposition it) in order to enable easy access to the receptacle for the purpose of connecting the male plug therein.

Therefore, one object of our invention is to provide an airflow-electric coupling which effects a sealed airflow connection between a conductor-carrying suction hose and the suction inlet opening of a vacuum cleaners tank unit while simultaneously effecting an electrical connection between energized electrical contacts located in the tank unit and the conductors carried by the hose.

Another object of our invention is to provide a safe airflow-electric coupling wherein energized electrical contacts, located in the region of the tank units suction inlet opening, are always concealed when conducting electricity to the hoses conductors, and even when the hose is disconnected from the tank, thereby substantially reducing the electric shock hazard which is possible with the prior art arrangement, hereinbefore described.

Another object of our invention is to provide an airflowelectric coupling which permits unlimited rotative movement of the hose about its longitudinal central axis when the hose is being manipulated during the surface cleaning operation.

Further objects as well as the various features and advantages of our invention will be apparent from the fol lowing description when considered in connection with the accompanying drawings which form part of the specification and of which:

FIG. 1 is a perspective view of a tank type vacuum cleaner embodying one embodiment of an airflow-electric coupling provided by our invention;

FIG. 2 is an exploded perspective view showing, among other things, a subassembly employed in a first embodiment of the plug unit of the subject airflow-electric coup FIG. 3 is a perspective view of a section of a flat, or strip-like, conductor carried by the vacuum cleaner suction hose;

FIG. 4 is a perspective view of the subassembly of FIG. 2 as assembled with the vacuum cleaner suction hose;

FIG. 5 is a perspective view as seen from a different vantage point and cut away for purposes of clarity of the assembly of FIG. 4;

FIG. 6 is an exploded perspective view partly cut away for purposes of clarity of a second subassembly which is also employed in the aforesaid first embodiment of the plug unit of our airflow-electric coupling;

FIG. 7 is an exploded perspective view of one element, a cylindrical cover 87, of the aforementioned second subassembly of FIG. 6 as seen from a vantage point different from the vantage point from which the element 87 is seen in FIG. 6;

FIG. 8 is a perspective view, cut away for purposes of clarity, showing the second subassembly of FIG. 6 in its assembled form;

FIG. 9 is a cross-sectional view of the subassembly of FIG. 8 as viewed along the section line 9--9 in FIG. 8;

FIG. 10 is a perspective view, also cut away for purposes of clarity, showing the second subassembly of FIGS. 6 and 8 as assembled with the first subassembly of FIGS. 4 and 5 to form the first embodiment of a completed plug unit of our airflow-electric coupling;

FIG. 11 is a longitudinal cross-sectional view of the plug unit of FIG. 10 as viewed along the section line 11--11 in FIG. 10;

FIG. 12 is a cross-sectional view of the plug unit of FIG. 10 as viewed along the section line 1212 in FIG. 1 1;

FIG. 13 is an end view of the cylindrical body 11 of the aforesaid first subassembly as viewed along the vantage line 1313 in FIG. 2;

FIG. 14 is an elevation view of one of the spring washer contact elements employed in the plug assembly of FIG. 10;

FIG. 15 is a side view of the spring washer contact element of FIG. 14;

FIG. 16 is an exploded perspective view of an electric receptacle and suction inlet conduit assembly employed in our airflow electric coupling shown together with the hinged end cover 66 and a seal-carrying cover plate 61 which are employed in the tank unit of a vacuum cleaner;

FIG. 17 is a perspective view from a different vantage point of a stationary annular ring member 41 employed in the assembly shown in FIG. 16;

FIG. 18 is a perspective view of a combination suction inlet conduit and electrical contact subassembly employed in the assembly of FIG. 16;

FIG. 19 is a perspective view showing the aforesaid stationary annular ring member 41 and an annular insulating ring 42 assembled in the end cover 66 of the vacuum cleaner tank unit;

FIG. 20 is a perspective view showing the receptacle assembly of FIG. 16 assembled with the combination suction inlet conduit and electrical contact subassembly together with the hinged front cover 66 of the vacuum cleaner tank unit just prior to assembling the seal-carrying cover plate 61 together therewith;

FIG. 21 is another perspective view similar to that shown in FIG. 20 but cut-away for purposes of clarity and showing the assembled plug unit of FIG. 10 as being initial-1y inserted into the suction inlet conduit and electrical receptacle assembly located in the tank units front cover 66;

FIG. 22 is another cut-away perspective view similar to that shown in FIG. 21 but showing the plug unit as being turned through a predetermined angle and securely latched so as to provide the required electrical and airflow connections between the suction hose and tank unit;

FIG. 23 is a longitudinal cross-section view showing the plug unit of FIG. 10 coupled with the receptacle and suction inlet conduit assembly as would appear if viewed along the section line 23-23 in FIG. 21;

FIG. 24 is an exploded perspective view of a second embodiment of a plug unit 1011 employed in the airflowelectric coupling provided by our invention shown together with a conductor-carrying suction hose;

FIG. 25 is a perspective view of one element, which is part of the plug unit of FIG. 24 shown rotated about FIG. 26 is a perspective view, cut-away for purposes of clarity, showing the completely assembled plug unit of FIG. 24 connected to one end of the conductor-carrying vacuum cleaner suction hose;

FIG. 27 is a longitudinal cross-section view of part of the assembled plug unit of FIG. 26 showing a latch mechanism which forms part of the plug unit 10a;

FIG. 28 is an exploded perspective view, partly cutaway, of a first subassembly forming part of a third embodiment of a plug unit 10b employed in the airflowelectric coupling according to our invention;

FIG. 29 is an exploded perspective view, partly cutaway, of one element, a cylindrical insulating body and its related inserts 142 and 143 of the exploded assembly of FIG. 28;

FIG. 30 is a perspective view of another element, a rigid tube 227, of the assembled plug unit 1012;

FIG. 31 is a perspective view of the plug unit 10b, partly cut-away, and completely assembled together with a suction hose having a conductor secured to the exterior thereof;

FIG. 32 is a cross-sectional view of the assembled plug 10b of FIG. 31 as viewed along the section line 3232 in FIG. 33; and,

FIG. 33 is a cross-sectional view of the assembled plug 10b of FIG. 31 as viewed along the section line 33-33 of FIG. 32.

In FIG. 1 there is shown a vacuum cleaner including a surface-agitating rotary brush 81 and incorporating an airflow-electric coupling provided by our invention. Our coupling is comprised of a plug and receptacle which are designated, generally, by the reference numbers 10 and 40, respectively; the plug 10 being in accordance with one illustrative embodiment of our invention. As suggested by the dotted arrow A the hollow plug 10, connected to the end of a suction hose 70, is intended for insertion in a suction inlet opening which is provided in the hinged end cover 66 of the cleaners tank unit 65. When so inserted, as shown in FIGS. 21 and 23, a protruding part 27a of a rigid tube 27 on the plug 10 enters a suction inlet conduit 43 which defines the suction inlet opening into the tank unit 65 through the end cover 66 thereof. Thus, a sealed airflow connection is made between the suction inlet conduit 43 and the suction hose 70 through the hollow plug 10. Also, after rotating the inserted plug 10, in the way hereinafter described, a set of electrical contacts 39 and 29 (FIG. 11) thereon makes contact with a set of energized electrical contacts 580 and 590 (FIG. 16), respectively, incorporated in the receptacle 40. Then, as suggested in FIG. 1, an insulated twowire conductor 72 carried by the hose 70 and connected with the plugs electrical contacts 29 and 39 transmits electricity to its end connector 76, which may be similar to a conventional female receptacle. From the receptacle 76 a conventional electric cord 78 carried in a separate conduit (not shown) incorporated in a rigid hollow wand 79, but separated from the airflow path in the wand, conducts electricity to an electric motor 82 which, together with the brush 81 which it rotates, is located in a carpet cleaning nozzle 80.

As the brush 81 rotates and agitates the carpet surface it dislodges dust, dirt and lint and the dislodged matter is carried away by vacuum-induced airflow, created in the tank unit 65 by a motor-fan unit 67. The airflow carrying the dislodged matter passes into the nozzle 80, through the wand 79 and through the hollow hose handle 77 which, as indicated in FIG. 1, is inserted into the upper end of the hollow wand 79. Thereafter, the airflow and dislodged matter passes through suction hose 70, the hollow plug 10, hollow receptacle 40 and the suction inlet conduit 43 (FIG. 23) into a dust bag 71 located in the tank unit 65. The inlet conduit 43 protrudes into the dust bag as shown in FIG. 23.

The plug 10, which is shown in its completely assembled form in FIG. 10, is intended to be connected to one end of the vacuum cleaner suction hose 70. The construction of the suction hose 70 is best illustrated at FIGS. 2 and 4. As shown, the hose carcass is comprised of a steel helical reinforcing wire 73 around which a wrapping 74 is placed; the wrapping 74 being rubberized nylon friction sheeting. Around the outer surface of the wrapping 74 the cord 83 which may be made of jute or the like is helically wound. The cord 83 is tightly wound in such a way that each turn of the cord is on the outside of the wrapping 74 but is situated between adjacent turns of the internal reinforcing wire 73. Thereafter, the carcass is vulcanized so that the friction sheeting or wrapping 74 becomes an integral body bonded to the internally situated helical reinforcing wire 73. Although the jute cord 83 may be removed after the vulcanization process, it is not necessary to do so. Thereafter, a fiat strip-like or tape-like insulated two-wire conductor 72 is helically wound about the outer surface of the hose carcass. The two-wire conductor 72 is comprised of a relatively thin strip of insulating material 720, such as polyethylene or the like, which has the fiat strip-like conductors 72a and 72b embedded therein, as shown in FIG. 3. These conductors 72a and 72b may be formed from copper or aluminum, or the like. Afterward, a sheath 75 is braided, in the well known manner, over the carcass and strip-like conductor 72.

The plug (FIG. 10) is comprised of two subassemblies. The first subassembly is shown in an exploded view in FIG. 2 and the second subassembly is shown in an exploded view in FIG. 6.

The first subassembly, shown in exploded form at FIG. 2, is comprised of: a hollow cylinder-like body 11 of dielectric material, such as nylon, polyethylene, or the like; the two electrically conductive slip rings 23 and 24, which may be made of Phosphor bronze, copper, beryllium copper, or the like; the two electrically conductive spring washers 25 and 26 (also shown at FIGS. 14 and which may also be made of Phosphor bronze, beryllium copper, or the like; a rigid tube 27 which may be made of steel, hard plastic, or the like; the two dielectric inserts 21 and 22, which may be made of the same material as the cylinder-like body 11; and, the split retaining ring 91 which may be made of a resilent material, such as plastic, steel or the like, and which can he slipped over an end of the suction hose 70 before assembling the other parts of the first subassembly.

FIGS. 4 and 5 suggest one way in which the first group of parts, comprising the first subassembly of FIG. 2, may be assembled and connected to the conductor-carrying suction hose 70. First, that end of the suction hose 70 which has the two-wire conductor 72 brought out from between the carcass and the sheath 75 (see FIG. 2) is inserted within the large central aperture provided in the cylinder-like body 11 until one end of the sheathed hose carcass abuts against an internal annular land 14 formed in the inside of the cylinder-like body 11. Then, the rigid tube 27 may be inserted into the central aperture of the cylinder-like body 11 and into the interior of the hose 70 until the external annular rim 27b of the tube 27 abuts against the annular front surface 15 of the cylindrical body 11. The inserted tube 27 due to its tight fit subjects the sheathed hose carcass to a relatively high pressure between the inside surface of body 11 and the outside of the tube 27. Thus there is provided a secure connection between the hose 70, body 11 and tube 27. But, to ensure a more secure connection an annular crimp 28 (FIGS. 5 and 11) is made in the inside wall of the tube 27 to subject the hose to an even greater pressure and thereby increase the frictional force resisting disconnection of the hose 70 from the body 11 and tube 27. Then, the larger diameter slip ring 23 and the smaller diameter slip ring 24 may he slipped over the outer surface of the cylinder-like body 11 so that one face of the larger diameter ring 23 and one face of the smaller diameter ring 24 bears against the external annular lands 12 and 13, respectively, which are formed in the outside surface of the cylindrical member 11. The rings 23 and 24 are provided with the integral terminal members or tabs 23a and 24a, respectively. The tab 23a is inserted within the longitudinal recess 18, or trough, in the outer surface of the cylinder-like body 11 and the tab 24a, after being passed through a slit 20 (FIGS. 2 and 13) provided in the surface of the external land 13, resides within the longitudinal recess 19, or trough, as shown in FIG. 4.

Before the end of the hose 70 is inserted into the cylinder-like body 11, the conductor 72 is arranged in the condition shown in FIG. 2; i.e., a short length of the conductor 72 is withdrawn from between the sheath 75 and the hose carcass and part of the insulation material 720 is stripped away to bare the two conductors 72a nd 72b. Then a short length of the conductor 72 is folded back on the outside of the sheath 75 and the hose end is inserted, with the conductor 72 still folded back, into the cylinder-like body 11 so that a relatively short length of the conductor 72 is situated between the sheathed hoses outer surface and the inside wall of the hollow cylinder-like body 11. Then, as suggested at FIGS. 4 and 5, a shorter length of the conductor 72 with the bared conductors 72a and 72b will remain exposed so that the bare conductors 72a and 72b can be folded again from the rear end of the body 11 and placed within the troughs 19 and 18, respectively, and subsequently bonded to the terminal members 24a and 23a, respectively, by soldering. In FIGS. 4 and 10 the reference numbers 23b and 24b indicate the masses of solder. Subsequently, the electrically conductive spring washers 25 and 26 may he slipped over the cylinder-like body 11 so that the larger diameter washer 25 bears against the ring 23 and the smaller diameter washer 26 bears against the ring 24. To complete the first subassembly two insulating inserts 21 and 22 are press fitted into the longitudinal troughs 18 and 19, respectively, which are provided in the outer surface of the cylinder-like body 11.

The second subassembly comprising the plug 10 is shown in the exploded view at FIG. 6 and is comprised of: another cylinder-like body 30 of dielectric material, such as nylon, polyethylene, or the like; two electrically conductve slip rings and 86 which may be made of the same materials as the slip rings 23 and 24; two elec-. trical contact elements 29 and 39 which may also be made of the same materials as the slip rings 23 and 24; and a hollow cylinder-like cover member 87 which may be made of steel, hard plastic, or the like.

One way of assembling the subassembly of FIG. 6 is suggested at FIGS. 7, 8 and 9. The slip ring 85 is inserted into the cylinder-like body 30 such that it bears against the internal annular land 34 for-med therein; the tab 85a, which is integral with the ring 85, being inserted into the recess 34a (FIGS. 11 and 12) which is provided in the land 34. Thereafter the other slip ring 86 is inserted within the body 30 until it bears against the larger diameter internal annular land 35 which is also formed inside the body 30. An electrical contact element 29 having the contact pin 29a, or terminal, connected therewith is inserted through a suitable aperture provided in the front face of the cylindrical body 30 until, as shown at FIG. 11, the pin 29a passes into an aperture in the tab member 85a, after which a rigid electrical bond is made between the pin 29a and tab 85a; e.g., with solder. Similarly, the pin-like contact 39a, or terminal, which is connected to the electrical contact element 39 passes through another suitable aperture provided in the cylindrical body 30 until, as shown at FIG. 11, it passes through the aperture 86a provided in the slip ring 86, after which the pin 39a is rigidly secured to the ring 86; e.g., by soldering.

When the contact elements 29 and 39 have been assembled as hereinbefore described they bear against the front faces of the projecting tab members 31 and 32, or key members, respectively, which are formed integrally in the outside surface of the cylindrical body 30. The body 30 may then be inserted as indicated in FIG. 8 within the cylindrical cover member 87 with the tab members 31 and 32 situated within the cup-like projections 88 and 89, respectively. After inserting the cylindrical body 30 into the cover member 87 a generally U-shaped leaf spring 95 (FIGS. 7 and 9) is inserted through a slot 90 in member 87 into a trough 38 formed in the outer surface of the body 30. Then, a latch member 92 is pivotally secured to the cover member 87 by means of the pivot pin 94 which passes through an inturned hollow cylindrical end of the latch member 92 and the two upright apertured ears 93. (See FIGS. 7 and 9.)

As indicated in FIG. 9 a forward portion 92b of latch member 92 is biased by the spring 95 such that the portion 92b is normally in abutment with a portion of the underside of the cover member 87 which is next to the slot 90. When the latch member 92 is depressed, against the restraint of the spring 95, an intermediate part 92a of the latch is moved downwardly together with the forward portion 92b into a recess 37 which is formed in the surface of the body 30 next to the trough 38.

To achieve the completed plug assembly shown at FIGS. 10 and 11 the second subassembly (FIGS. 8 and 9) is fitted over the first subassembly (FIGS. 4 and 5). In order to prevent longitudinal movement between the aforesaid first and second subassemblies a split retaining ring 91 which is formed from a resilient material, such as steel, nylon or polyethylene or the like, is circumferentially compressed and is allowed to expand to its larger circumference and thereby become inserted into the annular groove 36 (FIGS. 8 and 9) which is formed in the internal surface at the rear of the cylindrical body 30. (See FIGS. 10 and 11.) As shown in FIGS. 10 and 11 the retaining ring 91 also abuts an annular land 16 adjacent to an annular ridge 17, both of which are formed in the outside surface of the body 11. As indicated in FIG. 11, the annular land 16 has a small but sufiiciently large width dimension so as to provide a sufficiently large annular space between the inside surface of the cylindrical body 30 and the outer surface of the cylindrical body 11 to permit entry of the ring 91 into this annular space and into the annular groove 36.

Although the retaining ring 91 prevents axial movement between the cylindrical bodies 11 and 30 the outer cylindrical body 30, together with the slip rings 85, 86 and contact elements 29, 39 which are connected to the body 30, can be rotated through 360 degrees or more, clockwise or counterclockwise, about a longitudinal central axis which is common to both of the cylindrical bodies 11 and 30. As shown in FIGS. 10 and 11 the spring washer is situated between the slip rings 23 and 86 and the spring washer 26 is situated between the slip rings 24 and 85. When the electrical contact elements 29 and 39 have been electrically energized, in the way discussed hereinafter, then the conductors 72a and 72b, respectively, become electrically energized as follows: the slip ring 86 is energized through the pin 39a of the contact element 39 and the spring washer 25, being in contact with both the slip rings 86 and 23 conducts electricity to the latter slip ring. Then the tab 23a, or terminal, of the slip ring 23 is soldered to the conductor 72b thereby completing one line of the two wire circuit. Similarly, the slip ring becomes energized through the pin 29a of the contact element 29 and the spring washer 26 which is in contact with both of the slip rings 24 and 85 conducts electricity from the slip ring 85 to the slip ring 24. The tab 24a which is connected to the slip ring 24 being soldered to the conductor 72a completes the other line of the two wire circuit.

Regardless of the position to which the outer body 30 and its associated elements is rotated relative to the inner body 11 and its associated elements, the spring washer 25 will always be in pressure contact with both of the slip rings 23 and 86 and, similarly, the spring washer 26 will always be in pressure contact with both of the slip rings 24 and 85.

FIGS. 14 and 15 show the spring washers 25 and 26 in greater detail. However, although only one washer, representative of both of the spring washers, is illustrated in these figures it is to be understood that the spring washer 25 has a larger diameter than spring washer 26. Essentially, the spring washers 25 and 26 are resilient annular rings of an electrically conductive material, such as Phosphor bronze, beryllium copper, or the like. These annular rings have undulations circumferentially formed therein so that multiple contact areas are provided on each face thereof so that a good electrical contact can be achieved. Although three contact areas, on each face of the spring washers, are illustrated in FIGS. 14 and 15 it is to be understood that these spring washers may have more than, or less than, three such contact areas formed thereon.

In FIG. 16 there is shown an exploded view of the electrical receptacle and suction inlet conduit assembly 40 comprising the subject airflow electric coupling, together with an end cover 66 of the vacuum cleaner tank unit 65 as well as a cover plate 61. Basically, the receptacle and suction inlet conduit assembly 40 is comprised of: a stationary ring 41 which may be fashioned from aluminum, a hard plastic compound, or the like; a rotatable ring 42 which is formed from a dielectric material, such as nylon, polyethylene, or the like; a flanged suction inlet conduit 43 which is also formed from a dielectric material, such as nylon, polyethylene, or the like; the electrical contact elements 58 and 59 which may be formed from Phosphor bronze, beryllium copper, or the like; and the insulated two-wire electrical conductor 56 which includes the two separately insulated conductors 56a and 56b.

Also shown in FIG. 16 is a centrally apertured cover plate 61, which may be made of steel, including an elastomeric sealing gasket 62 which may be made of rubber. The gasket 62 encompasses the suction inlet conduit 43 and is for the purpose of providing an airtight seal when it abuts against the centrally apertured cardboard end cover 71a of a dust bag 71. (See FIG. 23.) In addition there is shown in FIG. 16 a hinged end cover 66 which is a fairly conventional end cover for a vacuum cleaner tank unit, with the exception, however, that the end cover 66 in this case is modified by having a large diameter circular aperture 60 formed centrally therein together with four holes 66a which are intended for receiving the four rivets 50.

The stationary ring 41 (FIGS. 16 and 17) has two outwardly projecting tabs 47 and 48 formed therein on the opposite peripheral edges thereof. These projecting tabs 47 and 48 each have two holes 49 provided therein for receiving the four rivets 50. As indicated the ring 41 has two keyways 45 and 46, or slots, formed therein on opposite sides of its large central aperture in line with the projecting tabs 47 and 48. In addition, there is provided in the ring 41 the three internally threaded holes 63 which are ultimately intended to receive and secure the three screws 64. In the rear face (FIG. 17) of the stationary ring 41 two arcuate alcoves 96 and 97 are formed therein adjacent to and concentrically disposed with respect to an annular cavity 98 formed in the ring 41. In the body of the ring 41 there is formed the apertured tab 99 which is intended to anchor one end of a coil spring 55.

As is indicated in FIG. 19 the rotatable annular ring 42 is assembled with the stationary ring 41 in such manner that the rotatable ring 42 is inserted into the annular cavity 98 so that the projecting tabs 53 and 54 formed in the rotatable ring 42 project into the alcoves 96 and 97, respectively. The rotatable ring 42 shown in FIGS. 16 and 19 has a large generally circular aperture formed centrally therein. At the periphery of this generally circular aperture there are formed the two keyways 51 and 52, or slots, which are spaced 180 apart in the inside periphery of ring 42. In addition there is formed in the outside periphery of the ring 42 the two projecting tabs 53 and 54; the tab 54 being apertured to receive an anchor the other end of the coil spring 55.

The suction inlet conduit 43 is illustrated in ample detail at FIGS. 16, 18 and 2023. The conduit 43 has formed at one end thereof a relatively large disc-like flange 43a. In the flange 43a there is formed two arcuate recesses 100 and 101, which recesses are really the concave sides of two raised portions 100a and 101a, respectively, which are formed in the flange 43a. Suitable pairs of apertures 102 102 are provided in both of the raised portions 100a and 101a. These apertures 102 are intended for receiving the pairs of rivets 58a and 59a in order to fasten the contact elements 58 and 59 within the recesses 101 and 100, respectively. The contact element 58 also includes a complementary pair of apertures (see FIG. 16) for receiving the pair of rivets 58a and a bent portion 58b which is intended to protrude through a slot -103 provided in the portion 101a so that, as shown in FIG. 20, the portion 58b may be bent in a reverse direction and can be connected to the conductor 56b by soldering. In addition, the contact element 58 has a resilient bent over contact portion 58c which is intended to make pressure contact with the contact element 39 on the plug in the manner hereinafter described (see FIG. 22). Similarly, the contact element 59 which is intended to be anchored in the recess 100 includes a complementary pair of apertures for receiving the pair of rivets 59a. In addition, there is provided the bent portion 59b which is intended to protrude through the slot 104 provided in the raised portion 100a so that, as indicated in FIG. 22, the portion 59b can be fastened to the conductor 56a with solder. Similarly, the contact element 59 includes a resilient bent over contact portion 590 which is intended for making pressure contact with the contact element 29 on the plug assembly 10.

One way of assembling the receptacle and suction inlet conduit assembly with the cover 66 and cover plate 61 is indicated in FIGS. 19-23. First the stationary ring 41, is as shown in FIG. 19, placed inside the hinged end cover 66 so that its smaller diameter central aperture is in registry with the larger diameter central aperture 60 in the end cover 66. Then the two pairs of rivets 50 are passed through the two pairs of holes 49 in the projecting tabs 47 and 48 as well as through the holes 66a in the end cover 66 to securely fasten the ring 41 within the end cover. The rotatable dielectric ring 42 is then placed ('FIG. 19) into the annular cavity 98 of the stationary ring 41 in such a way that the rotatable rings projecting tabs 53 and 54 project into the alcoves 96 and 97, respectively, of the stationary ring 41. When the opposite ends of the spring 55 are secured to the apertured tabs 99 and 54 of the rings 41 and 42, respectively, the rotatable ring 42 will be biased to the position shown in FIG. 19, which position, for convenience, is called the normal position. In the normal position the keyways or slots in the two rings 41 and 42 will be in registry; for example, the keyways 51 and 52 in the rotatable ring 42 are in registry with the keyways 45 and 46, respectively, of the stationary ring 41. When the contact elements 58 and 59 as well as the conductors 56a and 56b are assembled with the end flange 43a of the suction inlet conduit 43, the entire assembly may, as shown in FIG. 20, be fastened to the stationary ring 41 by means of the three screwes 64 which protrude through the holes 105 in the flange 43a and are ultimately secured in the internally threaded holes 63 in the stationary ring 41; the three holes 63 being in register with the three holes 105. Thereafter, the cover plate 61, as suggested in FIG. 20 and clearly shown in FIG. 23, is fastened to to the inside of the end cover 66. For this purpose the cover plate 61 is provided with holes 106 through which screws 107 pass and are received in the imternally threaded holes in the bosses 108 which are formed in the inside surface of the end cover 66.

FIGS. 21, 22 and 23 illustrate how our airflow-electric coupling comprising the first illustrative embodiment of our plug 10 and our receptacle 40 together with our suction inlet conduit 43 function to provide both an airflow path and an electrical connection, simultaneously. In FIGS. 21 and 23 the plug assembly 10 is illustrated as being inserted straight into the receptacle 40. In order to insert the plug 10 into the receptacle 40 the latch member 92 is depressed manually against the restraint of the spring so that the intermediate portion 92a, as well as the portion 92b, is moved within the recess 37. While the latch member 92 is so depressed, the plugs tabs 32 and 31 are lined up with the receptacles keyways which are defined by the registering pair of keyways 45-51 and 4652 so that the protruding portion 27a of the rigid tube 27 can enter for a considerable distance the suction inlet conduit 43. (See FIGS. 21 and 23.) However, as yet no electrical contact has been achieved between the contact elements of the plug 10 and the receptacle 40 because the contact elements 39 and 29 are still in facial contact with the face of the flange 43a which is a dielectric material. As indicated, the ring 42 covers and conceals the contacts 58 and 59 which are mounted within the recesses 101 and of the flange 43a. However, as the outer cylindrical body 30 of the plug assembly 10, together with its associated elements, is rotated clockwise according to FIG. 1, after insertion in the receptacle 40 but counterclockwise according to the orientation shown in FIGS. 21 and 22, the projecting tabs 32 and 31 being in the keyways 51 and 52 rotate the ring 42- against the restraint of the spring 55 to a position at which the contact elements 39 and 29 come into the contact with the contact surface portions 58:: and 59c which become uncovered as the keyways 51 and 52 arrive in registry with these contact surface portions thereby allowing an electrical connection between the contact elements 39 and 29 of the plug 10 and those contact elements 58 and 59 of the plug receptacle 40. After the plug 10 has been so inserted and I0- tated the housewife may stop depressing the latch member 92 and thereby allow the spring 95 to tend to urge the latch member 92 upwardly. When the aforementioned electrical continuity has been achieved the portion 92a of latch member 92 on the plug element 10, which was initially depressed against the restraint of the leaf springs 95, comes into line with the keyway 45 in the stationary ring and the intermediate portion 92a of the latch 92 moves upwardly into the keyway 45, thereby latching the plug assemby 10 in the position to which it has been rotated, which is the position at which the contact elements in the receptacle assembly and the associated ones in the plug assembly are in electrical contact, thereby enabling transfer of electrical energy from the tank unit to the hose conductors 72a and 72b and, ultimately, to the brush motor 82 in the floor cleaning nozzle 80.

The latch member 92 is one of the many features incorporated in our invention and it is especially advantageous for latching the plug in electrical continuity, as hereinbefore discussed, with the receptacle 40. The latch member 92 is also particularly advantageous in enabling an extremely easy unlatching of the plug 10 and receptacle 40 to electrically disconnect these two assemblies. Assume, for example, that the conditions are as illustrated in FIG. 22 whereat the intermediate latch portion 92a is situated in the keyway 45. In order to unlatch the plug 10 from the receptacle 40 all that need be done is to depress the latch member 92 so that the intermediate latch portion 92a moves downwardly and out of the keyway 45 so that the spring 55, as a consequence of its being stretched as shown in FIG. 22, will rotate the cylinder 30 of the plug 10 in a clockwise direction (according to the orientation shown in FIG. 22) to cause contact elements 39 and 29 to rotate away from the contact portions 58c and 590. Thus, the tabs 32 and 31 will also be rotated back (clockwise) to the positions shown in FIG. 21.

One of the characterizing features of the plug unit 10 which is used with the receptacle 40 and suction inlet conduit 43, is that because of the freely rotatable arrangement of the cylinder member 30, and its associated elements, relative to the cylindrical member 11, and its associated elements, the connected hose 70 and cylindrical body 11 can together rotate, freely, while the cylindrical member 30, when latched, as in FIG. 22, in the receptacle unit 40 is held stationary. Hence, with such an arrangement, one of the objects, hereinbefore stated, of our invention is achieved; i.e., the unlimited rotative movement of the hose 70 about its longitudinal central axis thereby overcoming the restrained movement of the prior art hose arrangements, hereinbefore described.

A second embodiment of our plug assembly identified by the reference number 10a is shown in FIGS. 24 through 27. This plug assembly 10a which is shown completely assembled in FIG. 26, is intended to be used with the same receptacle assembly 40 and suction inlet conduit 43, hereinbefore described. In the plug assembly 10a there are employed some elements which are also employed in the first plug 10 in FIG. 10. For example, the elements common to plugs 10 and 10a are the rigid hollow tube 27 and the cylindrical cover member 87. As suggested at FIGS. 24 and 26, the plug assembly 10a is intended to be connected to the end of the suction hose 70 which also has an insulated two-wire conductor 72 situated between its sheath and carcass. The construction and arrangement of the hose 70 and the two-wire conductor 72 has been described hereinbefore.

The plug assembly 10a is comprised of: a generally cylindrical hollow body 110 which is formed from a dielectric material, such as nylon, polyethylene, or the like; two semi-circular members 111 and 112 which are also formed from a dielectric material such as nylon, polyethylene, or the like and these semi-circular members 111 and 112 are intended to be inserted in an annular trough 113 which is formed in the outer surface of the dielectric body 110 (see FIGS. 24 through 27); the electrical contact elements 114 and 115 which are formed from a suitable electrically conductive material, such as beryllium copper, Phosphor bronze, or the like.

These conductor elements 114 and 115 have connected thereto the pins 114a and 115a, or terminals, which are intended to be passed through suitable apertures provided in the peripherally projecting tabs 116, 116a, 117 and 117a which, as shown in FIG. 24, are formed in the outer surfaces of the body 110 as well as in the members 111 and 112. The rigid hollow tube 27 may be formed from the same materials as hereinbefore indicated and the cylindrical cover member 87 may also be formed from the same materials as hereinbefore indicated.

The FIGS. 24-27 are suggestive of one way in which the plug assembly 10a may be put together to achieve the completed plug assembly shown at FIG. 26: After bringing out the bare conductors 72a and 72b from between the hose carcass and the sheath 75, the end of the hose is inserted within the cylindrical body until the front face of the hose carcass is in abutment with the annular land 118 which is formed in the inside surface of the body. (See FIG. 26.) The rigid hollow tube 27 may then be inserted into the body 110 so that the hose carcass becomes wedged between the inside surface of the body 110 and the outside surface of the tube 27. The inserted tube 27 due to its tight fit against the hose carcass will subject the hose carcass to a relatively high pressure between itself and the body 110. However, to ensure a secure connection, an annular crimp 28 (FIG. 27) may be made in the inside wall of tube 27 in order to subject the hose to an even greater pressure and thereby increase the frictional force resisting disconnection. Thereafter, the conductors 72a and 72b pass through the longitudinal slot 119 and thence into the annular trough 113, as shown at FIG. 26. The ends of these conductors 72a and 72b are then soldered to the terminal pins 114a and a, respectively, of the contact elements 114 and 115. Then, as shown in FIGS. 25 and 26, the two semi-circular members 111 and 112 are inserted into the trough 113 over the bare strip-like conductors 72a and 72b. These semi-circular insulating members 111 and 112 include the projecting tabs 116a and 117a which, as shown, are aligned with the tabs 116 and 117 on the body 110 so as to insulate the soldered connection of the conductors 72a and 72b with the terminal pins 114a and 115a respectively. FIG. 25 shows body 110 and members 111, 112 of FIG. 24 rotated about 120 to illustrate the construction and .arrangement of the rear side of these parts i.e. not seen in FIG. 4. The semi-circular insulating members 111 and 112 in FIG. 25 are assembled with the body 110. As shown, in FIGS. 25 and 27, the body 110 has a longitudinally recessed portion 120 formed in its outer surface and the semi-circular recess 120a arranged contiguously with the recessed portion is formed in the outer surface of the member 111. Therefore, when the semi-circular member 111 is arranged with the body 110, as shown in FIG. 25, the recesses 120 and 120a form a rectangular slot. In addition the semi-circular member 111 includes a downwardly tapering slot 121 formed therein, which together with a complementary slot 121a formed in the forward part of the body 110 define a unitary tapered slot. As will be appreciated from FIG. 27 the bent over leaf spring 95 is inserted within the rectangular slot formed by the recesses 120 and 120a. The intermediate latch portion 92a of the latch 92 is intended to function in the same manner as hereinbefore discussed with respect to the first embodiment of the plug member 10.

The fully assembled plug unit 10a (FIG. 24) shown in FIG. 26, is to be used in conjunction with the receptacle 40 and suction inlet conduit 43 hereinbefore described relative to the discussion relating to the plug unit 10. The plug unit 10a is, likewise, intended to be inserted into receptacle 40 and the inlet conduit 43 and then rotated so as to effect an electrical connection between the contacts 114 and 58c as well as the contacts 115 and 590. However, unlike the plug unit 10 (in which the hose 70 was rotatable together with the cylindrical member 11 relative to the cylindrical member 30) the hose 70 will not rotate relative to body 110 and the other elements connected with the body 110. The latch arrangement shown in FIG. 27 is operated in the same manner as hereinbefore described to latch and unlatch the plug unit 10a from the receptacle 40.

A third embodiment of our plug assembly is designated generally by the reference number 10b (FIG. 31) and is shown in FIGS. 28 through 33. This plug unit 10b, like those assemblies of the first and second plug unit embodiments 10 and 10a is also intended to be used in conjunction with the same receptacle 40 and suction inlet conduit 43, hereinbefore described. However, unlike the plugs 10 and 10a, the plug assembly 10b, is intended to be used with a suction hose 70 which carries a two-wire electric cord 123 on its outer surface next to its sheath 75.

For this purpose, a number of strap elements, such as the strap element 124, are employed as shown at FIG. 28 to secure the cord 123 along the outside of the hose 70. Like the plug unit assembly of the first embodiment this plug assembly 10b permits free rotative motion of the hose 70 relative to the receptacle 40, while electrical continuity is maintained between electric contacts in the plug assembly 10b and in the receptacle 40.

The plug assembly 10b is comprised of a first subassembly which is shown together with the hose 70 and cord 123 in an exploded view in FIG. 28 and a second subassembly which is the same as the second subassembly employed in the plug assembly 10; that is, the second subassembly is comprised of the separate elements hereinbefore described and illustrated in FIGS. 6 through 9. The complete plug unit 10b is shown in FIG. 31.

The first subassembly of plug unit 10b includes a generally cylindrical hollow body 125 which is formed from a dielectric material, such as nylon, polyethylene, or the like. Also provided is a receptacle 126, which when in a cavity'127 provided in the body 125, is adapted to receive a male electric plug 128 attached to one end of the cord 123. The receptacle 126 includes conductors 126a and 126b which, as will be appreciated from the discussion following, are intended to be connected to contact elements provided in the body 125. The slip rings 130 and 131 which are formed from an electrically conductive material such as Phosphor bronze, beryllium copper, or the like, are intended to be assembled with the hollow cylindrical body 125. In addition, the spring washers 132 and 133 which are formed from an electrically conductive material, such as beryllium copper, Phosphor bronze, or the like, are assembled with the slip rings 130 and 131 and are similar to those shown in FIGS. 14 and 15 on the body 125. The first subassembly also includes: a rigid hollow tube 227, which may be formed from metal or a hardened plastic compound; and the inserts 142 and 143 which are formed from a dielectric material, such as nylon, polyethylene, or the like.

' One way of assembling the plug unit 1011 is as follows: the receptacle -126 is first inserted within the cavity 127 provided in thebody 125 and the conductors 126a and 12 6b are laid in the long narrow slots 125a and 125b, respectively, which as shown in FIG. 29, are cut through the surface of the hollow body 125 and extend axially therealong away from the cavity 127. Then, the larger diameter slip ring 130 is slipped over the outside of the body 125 so that it bears against the external annular land 134providedin the outer surface of the body 25. Also, a projecting tab 130a which is integral with the slip ring 130 extends into the external slot 135 formed in the outside surface of the body 125 and a leading end portion of the projecting tab 130a lies over the slot 125a which is below the slot 135 and communicates with the slot 135. At this point the conductor 126a which is already situated in the "slot 125;: is soldered to the tab 130a. Similarly, the smaller diameter slip ring 131 is also passed over the body 125 'softhat' it bears against the external annular land 137 formed in the outside surface of the body 125. A projecting tab1131'a'vvhich is integral with the 'slip ring 131 passes intothe external slot 138 through a slit 139 in the annular (land 137; the slit 139 and land 137 being formed in the outside of'thebody 125. As a result a leading end portion of'the tab 131a 'lies over the narrow inside slot 125bwhichis below: and in communication with slot 138. they conductor 126b' already'situated in this slot 125b is soldered to. the tab 131a;Then the spring washer 132, .which is the larger diamt'erspring washer, is passed over ."the. outside of'the body 125 until it is in abutment with the slip ring 130. Similarly, the smaller'diameter spring washer" 133 is passed over the outside surface of the body 125' until it bears against the slip ring 131. The inserts 142-and 143, which being of dielectric material serve as'telectricinsulators, are inserted into the slots 125a and.125bv so that the soldered connections, hereinbefore 14 described, in these slots may be covered to electrically and mechanically protect such connections.

The suction hose 70 is afterward passed into the large circular aperture provided in the body until the forward end of the suction hose comes into abutment with the internal annular land formed in the inside of the body 125. Thereafter the rigid tube 227 may be inserted into the opposite end of the body 125, into the large central aperture therein, and, then, into the interior of the hose 70 until the external annular rim 227b of the tube 227 comes into abutment with the forward annular end 141 of the body 125. Then the inserted rigid tube 227 due to its tight fit subjects the sheathed hose carcass to a relatively high pressure between the inside surface of the body 125 and the external surface of the tube 227 to provide a secure connection between the hose 70 and the body 125. However, to ensure a secure connection an annular crimp 28 (FIG. 32) may be made in the inside Wall of the tube 227 to subject the hose to an even greater pressure and thereby increase the frictional force resisting disconnection of the hose 70 from the body 125.

The completely assembled plug unit 10b is shown in FIGS. 31-33. It is to be noted that the subassembly of FIG. 8 used in the first plug embodiment 10 is slipped over the body 125 and the elements assembled with the body 125.

The plug 10b is, like the plug 10, advantageous in that the hose 70 can rotate freely together with the body 125 when the plug 10b is connected with the receptacle 40 and suction inlet conduit 43, in a manner similar to that shown in FIGS. 21 and 22. Again, the latch 92 and its intermediate portion 92a functions in the same manner, to latch or unlatch the plug 10b in the receptacle unit 40, as hereinbefore described with reference to the discussion relating to FIGS. l-23.

While there has been described and illustrated more than one embodiment of our invention, it is to be understood that this has been done for the purpose of illustration only and that the scope of our invention is not to be limited thereby but is to be determined from the appended claims.

What is claimed is:

1. In a vacuum cleaner having a suction hose carrying electrical conductor means and a tank unit having a cover including a suction inlet to the tank unit; stationary electrical contact means located in the region of said inlet; an annular ring of dielectric material rotatable about its central axis and including at least one keyway therein, said annular ring being arranged concentrically with said inlet; a spring restraining said rotatable annular ring so that it normally covers said stationary contact means; means on said cover forming another keyway which is stationary relative to the rotatable annular rings keyway and in registration with the annular rings keyway when said annular ring is restrained in the aforesaid normal position; a hollow cylindrical body of dielectric material coupled to and encompassing one end of the suction hose, said hollow cylindrical body including at least one key member thereon; electrical contact means mounted on said key member and electrically connected with the hoses conductor means; an outwardly projecting spring-re- "strained movable latch mounted on said hollow cylindrical body and angularly spaced apart from said key member, said projecting latch being movable into a flush position with said cylindrical body to permit said hollow cylindrical body to be inserted coaxially Within said rotatable annular ring as said key member passes through said covers keyway and into said annular rings registering keyway, said cylindrical body being rotatable whereby said key member, being in said rings keyway, rotates said annular ring until said key members contact means come into contact with said stationary contact means and said flush latch is adjacent said covers keyway and is again projected outwardly by spring restraint into said covers keyway to lock said cylindrical body in the position to which it has been rotated.

2. In a vacuum cleaner having a suction hose carrying electrical conductor means and a tank unit including a suction inlet conduit, stationary electrical contact means within the tank unit, an annular dielectric ring including at least one keyway therein and arranged for rotation about said inlet conduits longitudinal central axis, a spring restraining said rotatable annular ring so that it normally covers said stationary contact means, means on said tank unit defining another keyway which is in registration with the rotatable annular rings keyway when said ring is restrained in the aforesaid normal position, a hollow cylindrical dielectric body coupled to one end of the suction hose, said hollow cylindrical body including at least one key member thereon, electrical contact means mounted on said key member and electrically connected with the hoses conductor means, an outwardly projecting spring-restrained movable latch mounted on said hollow cylindrical body and spaced from said key member, said projecting latch being movable to a flush position with said cylindrical body to permit said hollow cylindrical body to be inserted coaxially within said rotatable annular ring as said key member passes through said tank units keyway and into said annular rings registering keyway, said cylindrical body being rotatable whereby said cylindrical bodys key member, being in said rings keyway, rotates said annular ring until said key members contact means come into contact with said stationary contact means and said flush latch again projects into said tank units keyway by spring restraint to lock said cylindrical body in the position to which it has been rotated.

3. In a vacuum cleaner: a tank having a suction inlet opening; first electric contact means within said tank and in the neighborhood of said inlet opening; an insulating ring turnably mounted in said tank in a position normally covering said electric contact means, said ring having a slot therein; a hose adapted for being coupled to said inlet opening; first insulating means, connected to the outer surface of said hose; second insulating means turnably coupled with said first insulating means and engageable with said ring to turn said ring to align said slot with said first electric contact means; second electric contact means on said first insulating means, third electric contact means on said second insulating means for contacting said first electric contact means when said ring is turned to align said slot with said first electric contact means; and fourth electric contact means for continuously maintaining contact between said second and third electric contact means.

4. In a vacuum cleaner, a body having a suction inlet opening; first electric contact means in the body in the neighborhood of said inlet opening; an insulating member movably mounted in said body in a position normally covering said first contact means; a hose connectable to said inlet opening; first insulating means on said hose; second insulating means rotatably coupled with said first insulating means and engageable with said insulating member to move the insulating member so as to expose said first contact means; second electric contact means on said first insulating means; third electric contact means on said second insulating means in permanent electrically conductive relation with said second contact means and in contacting relation with said first contact means when the first contact means have been exposed.

5. The vacuum cleaner defined by claim 4 wherein said hose carries electrical conductor means which are connected to said second contact means.

6. The vacuum cleaner defined by claim 4 wherein said hose carries electrical conductor means which have an electrical connector coupled thereto, and said first insulating means including another electrical connector thereon coupled to said second contact means, said elecl6 trical connectors being adapted for being detachably electrically coupled with one another.

7. In a vacuum cleaner, a suction hose carrying electrical conductor means, a tank unit having a cover including a suction inlet conduit to the tank unit, said inlet conduit having an annular flange of dielectric material at one end thereof, first electrical contact means mounted on said annular flange, a ring of dielectric material rotatable about its central axis and including at least one keyway therein, a spring restraining said rotatable ring so that it normally covers said first contact means, means on said cover forming another keyway which is stationary relative to said rotatable rings keyway and in registration with said rings keyway when said ring is restrained in the aforesaid normal position, a first hollow cylindrical body of dielectric material connected to and encompassing one end of the suction hose, a second hollow cylindrical body including at least one key member thereon, said second cylindrical body concentrically encompassing said first cylindrical body and arranged for rotative movement therearound, second electrical contact means mounted on said key member and electrically connected with the hoses conductor means, an outwardly projecting spring-restrained movable latch mounted on said second cylindrical body and angularly spaced apart from said key member, a hollow tube protruding axially from the end of said hose and first and second cylindrical bodies; said projecting latch being movable into a flush position with said cylindrical body to permit said protruding hollow tube to become inserted within said inlet conduit as said sec-ond cylindrical body is inserted coaxially Within said rotatable ring and as said key member passes through said covers keyway and into said rings registering keyway, said second cylindrical body being manually rotatable whereby its key member being in said rings keyway rotates said ring until said second contact means comes into contact with said first contact means and said flush latch is adjacent said covers keyway and is again projected outwardly by spring restraint into said covers keyway to secure sad cylindrical body against further rotation, third electrical contact means on said first cylindrical body, said third contact means being connected to said conductor means, fourth electrical contact means on said second cylindrical body and connected to said second contact means, and fifth electrical contact means located between said third and fourth contact means for maintaining, electrical contact, continuously, between the third and fourth contact means as said relative rotative movement between said first and second cylindrical bodies is effected.

8. The vacuum cleaner defined by claim 7 wherein said fifth contact means is comprised of at least one resilient annular member having at least one undulation formed in its annular surface.

9. The vacuum cleaner defined by claim 4 further comprising at least one spring washer of electrically conductive material for maintaining said second and third contact means in said permanent conductive relation.

10. In a vacuum cleaner having means defining a suction inlet opening for receiving a hose the improvement comprising; stationary electric means in said vacuum cleaner having a first pair of contacts located in the re gion of said inlet opening and being accessible from the inside of said inlet opening, movable means consisting of dielectric material within said opening for normally coving said station-ary contacts whereby said contacts are then inaccessible from the inside of said inlet opening; a hollow cylindrical body attached to one end of said hose, said hollow cylindrical body being receivable telescopically within said inlet opening for connecting said hose to said vacuum cleaner, movable latching means on said hollow cylindrical body for engagement within said inlet opening for removably connecting said hollow cylindrical body ll. Said opening, a second pair of elec- 

1. IN A VACUUM CLEANER HAVING A SUCTION HOSE CARRYING ELECTRICAL CONDUCTOR MEANS AND A TANK UNIT HAVING A COVER INCLUDING A SUCTION INLET TO THE TANK UNIT; STATIONARY ELECTRICAL CONTACT MEANS LOCATED IN THE REGION OF SAID INLET; AN ANNULAR RING OF DIELECTRIC MATERIAL ROTATABLE ABOUT ITS CENTRAL AXIS AND INCLUDING AT LEAST ONE KEYWARD THEREIN, SAID ANNULAR RING BEING ARRANGED CONCENTRICALLY WITH SAID INLET; A SPRING RESTRAINING SAID ROTATABLE ANNULAR RING SO THAT IT NORMALLY COVERS SAID STATIONARY CONTACT MEANS; MEANS ON SAID COVER FORMING ANOTHER KEYWAY WHICH IS STATIONARY RELATIVE TO THE ROTATABLE ANNULAR RING''S KEYWAY AND IN REGISTRATION WITH THE ANNULAR RING''S KEYWAY WHEN SAID ANNULAR RING IS RESTRAINED IN THE AFORESAID NORMAL POSITION; A HOLLOW CYLINDRICAL BODY OF DIELECTRIC MATERIAL COUPLED TO AND ENCOMPASSING ONE END OF THE SUCTION HOSE, SAID HOLLOW CYLINDRICAL BODY INCLUDING AT LEAST ONE KEY MEMBER THEREON; ELECTRICAL CONTACT MEANS MOUNTED ON SAID KEY MEMBER AND ELECTRICALLY CONNECTED WITH THE HOSE''S CONDUCTOR MEANS; AN OUTWARDLY PROJECTING SPRING-RESTRAINED MOVABLE LATCH MOUNTED ON SAID HOLLOW CYLINDRICAL BODY AND ANGULARLY SPACED APART FROM SAID KEY MEMBER, SAID PROJECTING LATCH BEING MOVABLE INTO A FLUSH POSITION WITH SAID CYLINDRICAL BODY TO PERMIT SAID HOLLOW CYLINDRICAL BODY TO BE INSERTED COAXIALLY WITHIN SAID ROTATABLE ANNUALAR RING AS SAID KEY MMEMBER PASSES THROUGH SAID COVER''S KEYWAY AND INTO SAID ANNULAR RING''S REGISTERING KEYWAY, SAID CYLINDRICAL BODY BEING ROTATABLE WHEREBY SAID KEY MEMBER, BEING IN SAID RING''S KEYWAY, ROTATES SAID ANNULAR RING UNTIL SAID KEY MEMBER''S CONTACT MEANS COME INTO CONTACT WITH SAID STATIONARY CONTACT MEANS AND SAID FLUSH LATCH IS ADJACENT SAID COVER''S KEYWAY AND IS AGAIN PROJECTED OUTWARDLY BY SPRING RESTRAINT INTO SAID COVER''S KEYWAY TO LOCK SAID CYLINDRICAL BODY IN THE POSITION TO WHICH IT HAS BEEN ROTATED. 